经外周静脉置入中心静脉导管头端定位相关解剖参数的CT研究

目的 探讨经外周静脉置入中心静脉导管(PICC)头端定位的相关解剖参数,以指导PICC头端影像学定位。方法 选取2013年6月—2015年1月中南大学湘雅医学院附属肿瘤医院334例患者胸部薄层增强CT扫描的影像资料进行回顾性分析,分别测量患者右主支气管起点、右锁骨内侧头最上缘、气管隆突与心包返折及房腔交界之间的间距(解剖参数绝对值)。测量T₆椎体上缘平面至T₇椎体上缘平面之间距(T₆单元高度),将各解剖参数绝对值除以T₆单元高度,计算出解剖参数相对值。记录房腔交界和心包返折所对应椎体位置。结果 82%(274/334)的患者房腔交界位于T_6~7水平、79.3%(265/334)的患者心包返折位于T_5~6水平。气管隆突—房腔交界间距、气管隆突—心包返折间距、右主支气管起点—房腔交界间距、右主支气管起点—心包返折间距、右侧锁骨内侧头上缘—房腔交界间距及右侧锁骨内侧头上缘—心包返折间距的绝对值分别为(38.4±8.8)、(21.9±9.2)、(50.7±9.1)、(34.2±9.4)、(110.2±15.9)、(93.7±16.3)mm,相对值分别为(1.85±0.43)、(1.05±0.44)、(2.44±0.45)、(1.64±0.45)、(5.30±0.75)、(4.50±0.75)。相关性分析显示各解剖参数绝对值与患者身高有相关关系(P值均<0.01);而相对值与身高相关性明显减弱,并且部分解剖参数相对值与身高无相关性(P值均>0.05)。结论 气管隆突及右主支气管起点用于PICC头端定位的可靠性相对较好;而心包返折的位置变异较大,利用影像学标志推断心包返折的位置可能存在一定难度。

CT study on anatomical parameters for positioning the tip of peripherally inserted central catheter

Objective To investigate the anatomical parameters involved in positioning the tip of peripherally inserted central catheter(PICC).Methods Imaging data of 334 patients underwent contrast-enhanced thin-slice chest CT scan in the Affiliated Cancer Hospital of Xiangya School of Medicine of Central South University from June 2013 to January 2015 were retrospectively analyzed. Absolute value of anatomical parameters including distance between the upper margin of the right clavicular notch(RSCJ)and atriocaval junction (ACJ), distance between RSCJ and pericardial reflection(PR), distance between carina and ACJ, distance between carina and PR, distance between right tracheobronchial angle (RTBA)and ACJ, distance between RTBA and PR ,and the length of superior vena cava were calculated respectively. Each absolute value of anatomical parameter was divided by the height of the sixth thoracic vertebra body unit (T₆ unit), denoted as relative value of anatomical parameters correspondingly.Results The ACJs were identified at the level of T₆ or T₇ in 82%(274/334) of patients. The PRs were found at the level of T₅ or T₆ in 79.3%(265/334) of patients. The absoulute distance and relative distance (mean±SD) of carina-to-ACJ, carina-to-PR, RSCJ-to-ACJ, RSCJ-to-PR, RTBA-to-ACJ and RTBA-to-PR were (38.4±8.8),(21.9±9.2),(50.7±9.1),(34.2±9.4),(110.2±15.9),(93.7±16.3 )mm, and (1.85±0.43), (1.05±0.44), (2.44±0.45),(1.64±0.45), (5.30±0.75),(4.50±0.75), respectively. The correlation analysis showed the absolute values of anatomic parameters were highly related with the patients’ heights (P<0.01), while the relative values were significantly weakened with the patients’ heights and the partial relative values of anatomic parameters were not related with the patients’ heights(P>0.05).Conclusions Both carina and right tracheobronchial angle might serve as relatively reliable imaging landmarks for positioning the tip of PICC. Imaging landmark guided estimating the position of PR may be relatively difficult due to the varied position of PR.